Tool-holder



CHARLES JERME CLBJK, 0F LMEWQ, EO.

TOL-HLD l' n To all whom it may concern Be it known that I, CHARLES JEROME CLARK, a citizen of'the United States, residing at Lakewood, in the county of Cuyahoga and State of Ohio, I'have invented certain new and' useful improvements in TooLHoldi ers, of which the following is a specification.

This invention pertains to tool holders and more particularly to that class wherein the holder proper (or the element by which it is carried) may partake of a lateral movement while still being driven by the operat ing means. l'nother words the tool be it a drill, tap, or reamer, may while rotating and accomplishing work, stand oft center with reference to the driving element.v

rlhe main object of the present invention is to'providexa floating tool holder which, by reason of its construction, will be so sensitive that it may, for instance, be employed with drills of small diameter, the arrangement of the parts being such that a slight touch of the drill point upon the jig or guide bushing Iwill cause the drill to be moved laterally while still maintaining its proper angular relation to the work. y

I am aware that various iioating or selfalining tool holders have heretofore been proposed and no broad claim is made to such a structure; the arrangement hereinafter set forth, however', is highly sensitive and capable of performing work which has notl so :t'ar as I am advised been accomplished with tool holders of the type under consideration.

IThe holder forming the basis of my invention is illustrated inu the annexed drawings wherein Figure 1 is a side elevation of the holder, the tool chuck being omitted.

Fig. 2 a top plan view thereof,

Fig. 3 a vertical sectional elevation, and

Fig. 4 a side elevation of a portion of a drill press with my tool applied thereto, a jig and work holder.

In the drawings, 1 denotes a cup shaped element or housing having a centrally disposed opening 2 forme-d in the bottom there ot'. The upper end of said member is internally threaded and a cap piece or head '3 is screwed therein, a lock nut l being pro-- vided to hold the parts against relative movement once they are brought to their desired adjusted position. A tapered shank 5 formed integrally with the headhextends upwardly therefrom, the shank being pro- Speecation of Letters latent.

Patented Noi/'29, 1921.

Application :filed January 25, wel. Serial No. 439,846.

vided with a longitudinally disposed bore or recess 6 forming the housing for a centering pin 'i' and a spring 8 which tends at all times to torce the pin downwardly. rlhe inner `face of the head 3 .is provided with a transversely disposed slot ,Sinto which rojects the upper tongue or rib 10 of an 81dham coupling element 11. Said rib is provided ajt its midlength with an inverted cone shaped seat or socket 12 into which extends the coned end 13 of pin 7.

rlhe lower tongue or rib la ofthe coupling element takes into a slot 15 formed in a head or enlargement 16 formed as an integral part or secured to the upper end of a spindle 1'?. Said spindle is counterbored or formed with a socket or recess in which'is mounted a spring g 18 and a second centering vpin 1E?, the tapered end of the latter extend ing into a. conical seat or recess formed centrally of the lower cross rib 11i.

'lhe spindle is of such diameter that it passes freely through opening 2; in other words the opening is materially larger than the spindle so that the latter may shiftlaterally without contacting the walls of the opening. A. thrust plate or flange 20 is secured to or *formed integrally with Athe of the thrust plate and an overlying annular' shaped bearing element 24. K

Said bearing element is held in placeby a ring 25 interposed between the element and the lower depending edge of the cap piece or head 3. By screwing the head in or out, as Y the case may be, proper adjustment of the parts may be elected after which the lock nut e is turned hometo secure the parts in place. Y

Spindle 17 isdesigned to have attached or secured to thereto a chuck as 26, Fig. 4, in which view the holder as above described is shown with its shank 5 in associated work` ing relation with a drill press. The drill designated by 27 carried by the chuck is shown as standing out of line with the jig bushing 28, this by reason of the fact that the workman has failed to properly posi tion the jig; a condition which will frequently occur in actual practice..

The drill pon desrending eontarts the inehnedor curved wall ot'l'the bushingr and will move bodllj,v into line'wilh the opening;

l in the bushing through which it passes.

4nloove Set forth, the Oldham ronpling being relieved ot' any pressure dueto `the presenre of `the thrust bearings. Furthermore by the lprovision of the two oppositelv disposed spring actuated centering pins wouldnty upon lopposite sides of the coupling elenient 11 an "equilibrium of centering forces is lexerted upon said element as it shifts or tloats around ,to accommodate itself to the oil4 eenter po- .29..

sition of the spindle element 1T and its allied parts'.

While the ho de as above set forth is especially adapted ttor light drilling` it may, as above noted, be employed equally as well upon heavier work such as tappingr and teaming.

It manifest that the ring Y25 may be omitted and the head lmay be ot' sueh length as to directly taking;l the plaeelot' said ring.

lVhat claimed is l. n a tool holder of the floating type, the combination of a spindle; a driving element therefor; an Oldham coupling,r interposed between .thesameg means/acting upon said eou pling and independent otx the driving eonneetions thereofy to aline the spindle and driving element; and a thrust hearing eooperating with' the spindle to relieve the couplingr from pressure exerted upon the spindle. 1

2. ln a tool holder of the floating' type, the combination of a cup-shaped shell having an opening in its lower wall; a spindle extending.;r through Said opening; a beariner plate rotatable with the spindle and loeated .withont-act the element 24 thus' in the shell; a serond bearing plate located within the shell; balls loeated between the said two plates and between the first plate and the lower 'all oiI the shell; a head on the spindle and rotatable therewith; a shank having' a head the latter being' secured within the upper end otl the rop-shaped shell;a coupling element o'i" the Oldham type interposed between said heads; and means:ae-tiner constantly to center the element-'and to eonsequently alinethe shank and spindle.

3. ln a tool holder of the floatingr type, the combination ot' a cup-shaped shell having an openingv in the lower portion thereof; a spinille extending' through said openin r and out otveontaet with the walls thereof; a head upon said spindle; a bearing plate carried by the spindle at a point below the head; a shank; a cap piece formed with said shank and. threaded into the upper end ot' the shell; an Oldham couplingv interposed between the lap and head; a spring pressed pin mounted in each ot' the shank and spindle and eooperating` with the coupling to center the same; a bearing' ring located withinthe shell below the head; said ring beingr held in place by the eap piece; and antifrietion bearing interposed between said ring.;r and bearing plate, and between the plate and the inner face of the bottom of the eup-shaped member.4

4. In a tool holder of the loatmg type, the combination of a. spindle; a driving element therefor, an Oldham coupling interposed between said parts to permit lateral movement ot the spindle with reference to the driving element; a bearing member-niovable with the spindle and independent of the elements oi said coupling; and anti-friction bearingv elements.roperating with the bearing member, whereby Ythe coupling is relieved from thrust CHARLES JnnoMn einen'.

' and the spindle rendered sensitive to lateral p 

